The present invention relates to doping of iridium or iridium rhenium alloys with molybdenum and hafnium.
International patent application publication No. WO 2004/007782 mentions crucibles for crystal growing as one of many applications for iridium. Iridium alloys containing tungsten and/or zirconium are described, which additionally contain 0.01 to 0.5% by weight of further elements such as molybdenum and hafnium and, optionally, contain ruthenium in a quantity of 0.01 to 10% by weight. In this document, it is also mentioned that the addition of these additional elements, as such, alone is not effective.
U.S. Pat. No. 4,444,728 describes iridium rhenium crucibles with a rhenium content of 1 to 15% by weight.
According to U.S. Pat. No. 3,918,965, the mechanical properties of iridium are greatly improved by doping with 0.65 to 0.93% by weight of hafnium.